U.S. Pat. No. 3,729,609, assigned to the assignee of this application, discloses electrical discharge machining apparatus in which a plurality of substantially parallel wire electrodes are used to concurrently machine a plurality of small holes in a workpiece. The patent discloses apparatus in which the electrodes are manually refed following each machining cycle to compensate for electrode erosion that took place during the preceding cycle. It is an object of the present invention to provide improved electrical discharge machining apparatus of multiple electrode type in which the electrodes are automatically mechanically refed following each machining cycle to compensate for erosion.